Despite the robustness of OFDM (Orthogonal Frequency Division Multiplex) multi-carrier modulation compliant with the DVB-T (Digital Video Broadcast Terrestrial) standard chosen for the transmission of digital channels, measurement campaigns have revealed reception problems, particularly in the context of portable television reception.
Unlike an analogue signal in which the degradation is gradual, a fading phenomenon affecting the digital signal at a given time, over a given area, generates a rapid transition from quality reception to total loss of signal. The result is that the launch of the DVB-T programme is dependent on devising technical solutions for antennas to allow quality reception.
In the context of television reception in the UHF band, the antennas currently developed provide a directivity of a few dB (decibels), with the choice of polarization being entirely manual. These large and rather impractical antennas offer limited reception quality.